Atherosclerosis and its associated vascular complications are the principal cause of cardiovascular and cerebrovascular diseases leading to heart attacks and strokes. Atherosclerosis is a disease characterized by deposits of fatty material or plaques on the inner walls of the arteries. Over time the plaque deposits increase in size blocking oxygen from reaching the downstream organs. When vital arteries to the heart are blocked, it can cause angina and heart attack and possibly leading to death. Atherosclerosis also affects the arteries leading to the brain causing cerebral thrombosis or a stroke which can result in muscular paralysis, loss of cognitive capacity and the risk of dementia. Arteries in the leg may also become blocked with atherosclerotic plaque causing pain and difficulty in walking and possibly the risk of necrosis and gangrene of the effected tissue.
Atherosclerotic plaque is theorized to be caused by the interaction of monocytes migrating across the arterial wall in response to accumulation of oxidized cholesterol. Inside the arterial wall, the monocytes engorge themselves on the oxidized cholesterol and are converted into fat-laden “foam cells.” When the foam cells die, they release their lipid content, creating a lipid core inside the arterial wall. The buildup of the lipid core along with calcium, fatty acids and other materials eventually form plaque. Over time the plaque calcifies and hardens. Continued plaque growth within the arterial wall causes the arterial wall to expand outward to avoid encroaching into the lumen. When the plaque growth reaches beyond the capacity of the arterial wall to compensate, the plaque intrudes into the lumen. Rupturing of the plaque exposes the lipid core to the blood creating blood clots. The clots can block the artery cutting off blood flow or detach and obstruct an artery downstream. Patients suffering from atherosclerosis may be asymptomatic for many years while the atherosclerotic plaque builds up in the arterial walls. Most often patients are unaware of the disease until a stroke or heart attack occurs.
Most methods for treating atherosclerosis involve uses of prescription medication. For instance, the group of medications known as statins are prescribed for treating atherosclerosis in patients with high cholesterol but its effects in women and people over the age of 70 are unclear. Niacin, a vitamin, has also been prescribed for treating atherosclerosis but it causes flushing of the skin and increases blood sugar levels which can be risky for diabetic patients. Drugs for limiting the absorption of cholesterol like Ezetimibe have also been prescribed for patients with atherosclerosis but its efficacy in reducing the risk of heart attacks and strokes in those patients is unclear.
Other methods for treating atherosclerosis include medical procedures such as surgical stenting, surgical excision of the plaque, ablation of the plaque, and bypass surgery/grafting. These procedures are costly and not without risks and limitations. Stenting of the arterial wall comes with the risks of blood clots and the stent itself can become blocked over time. Surgical excision and ablation can release plaque particles that can lead to obstruction of arteries leading to the brain causing a stroke. Grafting the arteries with autologous blood vessels can also lead to other complications such as stroke, heart attacks, reduced kidney function and irregular heartbeats. All these surgical procedures are also severely limited by targeting only specific arteries and leaving other arteries that may be affected by atherosclerosis untreated.
Atherosclerosis can be prevented or mitigated by modification of risk factors such as smoking cessation, increase exercise, managing weight in obese patients, lowering blood pressure, monitoring blood lipid levels and changing poor dietary habits. Additionally, patients at risk of developing atherosclerosis are advised to reduce their cholesterol and saturated fat intake by substituting their diets with unsaturated fatty acids found in natural oils such as olive oil. Olive oil and other naturally occurring oils, however, also contain other undesirable fatty acids that has been known to contribute to atherosclerosis.
Despite the advances in the study, prevention, and treatment of atherosclerosis, it remains a leading cause of death or disability in people. Accordingly, there exists a need for effective treatment of atherosclerotic plaques without the need for invasive medical procedures and risky side effects from prescription pharmaceuticals.